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Point B is the center of the circle shown, and the length of arc AC is 8π. What is the area of the circle?

Point B is the center of the circle shown, and the length of arc AC is 8π. What is-example-1

2 Answers

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Answer:

A

Explanation:

User Ian Jacobs
by
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3 votes

Answer:


A=324\pi \text{ units}^2\approx1017.88\text{ units}^2

Explanation:

The formula for arc length is:


\stackrel{\frown}{A}=2\pi r((\theta)/(360)})

Where Θ is measured in degrees.

We know that the arc length is 8π when the degree is 80. So, substitute 8π for A and 80 for Θ:


8\pi=2\pi r((80)/(360))

Divide both sides by 2π:


4=r(80)/(360)

Simplify the fraction:


4=(2)/(9)r

Multiply both sides by 9/2:


r=18

So, the radius is 18.

Now, we can find the area of the circle. The formula for the area of a circle is:


A=\pi r^2

Substitute 18 into r:


A=\pi (18)^2

Simplify:


A=324\pi \text{ units}^2\approx1017.88\text{ units}^2

And we're done!

User Drew Hunter
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3.9k points